wp-admin/includes/file.php:674$filenamestringoptional''$dirstringoptional''stringfunction wp_tempnam( $filename = '', $dir = '' ) { if ( empty( $dir ) ) { $dir = get_temp_dir(); } if ( empty( $filename ) || in_array( $filename, array( '.', '/', '\\' ), true ) ) { $filename = uniqid(); } // Use the basename of the given file without the extension as the name for the temporary directory. $temp_filename = basename( $filename ); $temp_filename = preg_replace( '|\.[^.]*$|', '', $temp_filename ); // If the folder is falsey, use its parent directory name instead. if ( ! $temp_filename ) { return wp_tempnam( dirname( $filename ), $dir ); } // Suffix some random data to avoid filename conflicts. $temp_filename .= '-' . wp_generate_password( 6, false ); $temp_filename .= '.tmp'; $temp_filename = wp_unique_filename( $dir, $temp_filename ); /* * Filesystems typically have a limit of 255 characters for a filename. * * If the generated unique filename exceeds this, truncate the initial * filename and try again. * * As it's possible that the truncated filename may exist, producing a * suffix of "-1" or "-10" which could exceed the limit again, truncate * it to 252 instead. */ $characters_over_limit = strlen( $temp_filename ) - 252; if ( $characters_over_limit > 0 ) { $filename = substr( $filename, 0, -$characters_over_limit ); return wp_tempnam( $filename, $dir ); } $temp_filename = $dir . $temp_filename; $fp = @fopen( $temp_filename, 'x' ); if ( ! $fp && is_writable( $dir ) && file_exists( $temp_filename ) ) { return wp_tempnam( $filename, $dir ); } if ( $fp ) { fclose( $fp ); } return $temp_filename;}Introduced in 2.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/file.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.